The present invention relates to a magnetic field generating apparatus and an MRI (Magnetic Resonance Imaging) apparatus, and particularly to a magnetic field generating apparatus for generating a magnetic field in a vertical direction, and an MRI apparatus using the magnetic field in the vertical direction.
An MRI apparatus is configured to reconstruct an image based on magnetic resonance signals collected by applying a static magnetic field, a gradient magnetic field, and an RF (radio frequency) magnetic field to a subject. In an MRI apparatus of a vertical magnetic field type, a pair of magnets disposed to face each other in a vertical direction generate a static magnetic field. The static magnetic field is generated such that its region of homogeneous magnetic field intensity has a spherical shape (see Patent Document 1, for example).
[Patent Document 1] Japanese Patent Application Laid Open No. 2001-070284.
Although a static magnetic field desirably has magnetic field intensity as high as possible and a region of homogeneous magnetic field intensity as large as possible, a magnet whose magnetic pole has a large surface area and a commensurately large magnetic circuit are required accordingly, unavoidably leading to increased cost.